There are already known plastics material containers of a generally cubic shape, for containing for example foodstuffs and luxury foods such as yogurt. Such containers have projections and recesses which can be brought into engagement with each other so that when the containers are empty, a plurality of such containers can be fitted together on the so-called building block principle to compose larger units. Such units then in turn can be used for other purposes, for example as toys, in order in this way to permit multiple re-use and in addition to counteract environmental pollution which would otherwise occur due to the discarding of such throw-away packaging. In these known containers however the corresponding projections and recesses are disposed in the region of the eight corners of the container, so that additional assembly supports and recesses must be provided at the walls of the containers in order for the combined units formed by such containers to achieve a sufficient degree of stability. However such supports and recesses make it more difficult to combine such containers together and thus limit the range of possible re-uses.